Potassium and phosphorus repletion in hospitalized patients: implications for clinical practice and the potential use of healthcare information technology to improve prescribing and patient safety

ABSTRACT

Objectives: Evaluate potassium and phosphorus repletion in hospitalized patients. Assess the potential role for use of various methods, including healthcare information technology, to improve prescribing and patient safety.

Research design and methods: Inpatient medication profiles were screened to identify orders for potassium and phosphorus replacement products. Electronic laboratory and medical records were used to evaluate efficacy and safety. Eligibility for oral therapy was defined by the presence of other scheduled oral medications on the medication profile. Appropriateness of prescribing was based on adherence to the hospital guidelines for repletion.

Results: Overall, 134 orders for potassium in 92 patients and 36 orders for phosphorus in 27 patients were evaluated over a 3-week data collection period. Intravenous (IV) potassium was prescribed in 73% of replacement episodes (46% as single doses and 54% within large volume IV fluids), with 85% for normokalemia or mild-to-moderate cases of hypokalemia. Phosphorus orders involved single doses of IV potassium phosphate (mean 13.1 mmol) in 75% of cases. Approximately 85% of doses were for mild or moderate hypophosphatemia. Eligibility for oral therapy was evident in 74% of normokalemic or mild hypokalemic cases receiving IV potassium products and in 33% of cases receiving IV phosphorus replacement. Six cases of mild hyperkalemia were observed. No hyperphosphatemia was documented.

Study limitations include use of a retrospective design, inability to discern whether some electrolyte doses were given with a preventative intent, potential overestimation of the number of patients eligible for oral repletion, and lack of data on the accessibility of the laboratory serum concentrations or the awareness of serum values to the prescribers.

Conclusions: Intravenous potassium and phosphate products are commonly prescribed for mild or moderate cases of hypokalemia or hypophosphatemia. Many patients met eligibility for oral therapy. Efforts to enhance prescriber education and implement computerized prescribing and decision support systems have the potential to improve prescribing and reduce possibilities of adverse drug events and medication errors related to potassium and phosphate administration.     

A case of familial tumoral calcinosis/hyperostosis–hyperphosphatemia syndrome due to a compound heterozygous mutation in GALNT3 demonstrating new phenotypic features

Summary  A new case of familial tumoral calcinosis (FTC)/hyperostosis–hyperphosphatemia syndrome (HHS) due to a novel compound heterozygous mutation in N-acetylgalactosaminyltransferase 3 (GALNT3) and with new phenotypic findings is presented. The response in serum phosphate and fibroblast growth factor 23 (FGF23) to medical treatment is detailed. This case expands the genotype and phenotype of FTC/HHS and gives insight into its treatment and pathophysiology. Introduction  FTC and HHS are caused by mutations in FGF23, GALNT3, or KLOTHO. They are characterized by hyperphosphatemia, increased phosphate reabsorption, and elevated or inappropriately normal serum 1,25-dihydroxyvitamin D₃ (1,25-D₃); FTC is associated with calcific masses, and HHS with diaphyseal hyperostosis. Methods  A 36-year-old woman presented with abnormal dental X-rays at age 12 and was hyperphosphatemic at 22. She underwent radiographic, biochemical and genetic testing, and medical treatment. Results  Serum phosphorus was 7.3 mg/dL (2.5–4.8), TmP/GFR 6.99 mg/100 mL (2.97–4.45), 1,25-D₃ 35 pg/mL (22–67). Radiographs revealed tooth anomalies, thyroid cartilage calcification, calcific masses in vertebral spaces, calcification of the interstitial septa of the soft tissue in the lower extremities, and cortical thickening of the long bones. Her total hip Z score was 1.9. C-terminus serum FGF23 was 1,210 RU/mL (20–108), but intact FGF23 was 7.4 pg/mL (10–50). DNA sequencing determined she was a compound heterozygote for mutations in GALNT3. Treatment with niacinamide and acetazolamide decreased TmP/GFR and serum phosphate, which was paralleled by a decrease in serum C-terminus FGF23. Conclusions  This case broadens the spectrum of phenotypic and genotypic features of FTC/HHS and suggests treatments to decrease renal phosphate reabsorption in the setting of a low intact FGF23.     

蔗糖蜜生产酵母中磷的吸光光度测定法

目的探讨蔗糖蜜生产酵母中磷测定的样品制备与吸光光度分析方法。方法利用三氯乙酸、TritonX-100、柠檬酸混合溶液对样品的磷含量进行有效消解、浸提,并用吸光光度法进行测定。结果该方法测定结果满意,平均回收率（n=5）达96.4％-101.6％,变异系数为1.4％-1.6％。结论该样品处理及测定方法简单方便、经济实用。     

对血液透析患者钙磷代谢异常改进治疗的研究

目的改进对血液透析患者钙磷代谢异常的治疗,观察患者生活质量的改善。方法按照美国肾脏基金会（NKF）制定的“慢性肾脏病,透析病人生存质量指南（K/DOQI）”改进对血液透析患者钙磷代谢异常的治疗,观察1年后患者的血清钙、磷、钙磷乘积、全段甲状旁腺素（iPTH）等水平及治疗达标率的变化。应用肾脏病调查表（KDQ）评估患者生活质量的改善。结果改进治疗后患者的血清钙、磷、钙磷乘积及iPTH水平均较改进治疗前有明显下降（P〈0．01或〈0．05）。改进治疗后治疗达标率分别为：血清钙74．42％（32／43）、血清磷62．79％（27／43）、钙磷乘积55．81％（24／43）、iPTH60．47％（26／43）、四项达标25．58％（11／43）,均较改进治疗前有明显上升（P〈0．01或〈0．05）。改进治疗后KDQ评分的总分及各方面得分均较改进治疗前有明显增中（P〈0．01）。结论改进治疗后患者钙磷代谢隋况较改进治疗前改善,生活质量提高。     

对血液透析患者钙磷代谢异常改进治疗的研究

目的 改进对血液透析患者钙磷代谢异常的治疗,观察患者生活质量的改善.方法按照美国肾脏基金会(NKF)制定的"慢性肾脏病,透析病人生存质量指南(K/DOQI)"改进对血液透析患者钙磷代谢异常的治疗,观察1年后患者的血清钙、磷、钙磷乘积、全段甲状旁腺素(iPTH)等水平及治疗达标率的变化.应用肾脏病调查表(KDQ)评估患者生活质量的改善.结果改进治疗后患者的血清钙、磷、钙磷乘积及iPTH水平均较改进治疗前有明显下降(P<0.01或<0.05).改进治疗后治疗达标率分别为:血清钙74.42%(32/43)、血清磷62.79%(27/43)、钙磷乘积55.81%(24/43)、iPTH 60.47%(26/43)、四项达标25.58%(11/43),均较改进治疗前有明显上升(P<0.01或<0.05).改进治疗后KDQ评分的总分及各方面得分均较改进治疗前有明显增加(P<0.01).结论改进治疗后患者钙磷代谢情况较改进治疗前改善,生活质量提高.     

添加化学试剂控制湖泊底泥内源磷释放的实验研究

目的 研究添加化学试剂对湖泊底泥内源磷释放的抑制效果,为城市内湖综合治理措施的制定提供技术依据.方法 于2008年5月20日,采集莫愁湖上层底泥样品和水样.对底泥进行磷形态[总磷(TP)、NaOH-P、HCl-P、无机磷(IP)、有机磷(OP)]的分析,测定水样的pH值和TP的含量.分别向水(250ml)-底泥(10g)系统中投加0～1 000.0mg/L的Ca(OH)_2、0～10.0 mg/L的Al_2(SO_4)_3和0-25.0mg/L的FeCl_3,测定水样pH值和TP的含量,并计算TP的释放控制率.结果 莫愁湖水样的pH值在7.6～8.0之间,TP含量为2.0 mg/L.底泥中的TP、HCl-P、NaOH-P、IP、OP的含量分别为2 187.06、1 383.89、526、48、1910.37、276.69mg/kg.随着Ca(OH)_2:浓度的增加,水体pH值迅速上升,TP含量呈下降趋势,TP的释放控制率呈升高趋势.随着Al_2(SO_4)_3 或FeCl_3浓度的增加,水体pH值略有下降,TP含量呈下降趋势,TP的释放控制率呈升高趋势.结论 Ca(OH)_2、Al_2(SO_4)_3、FeCl_3对湖泊底泥内源磷的释放具有明显的抑制作用.     

32P-磷酸铬-聚 L-乳酸缓释粒子的制备及其放射性释出和生物分布

Objective The aim of this study was to prepare the 32P-chromic phosphate-poly(L-lac-tide) (32P-CP-PLLA) particles with different ratio of the materials and further examine their performance in-dex in vivo and in vitro and their intracorporeal distribution. Methods The erosion, degrading rates, de-layed release velocity and radioactivity self-absorption coefficient (RSAC) of 32P-CP-PLLA particles made from different materials were investigated and compared. After the implantation of 32P-CP-PLLA particles and the injection of 32P-CP colloids in the muscular tissues, the weight loss rate and the radioactivity release rate (RRR) of the particles were calculated. The intracorporeal distribution, radioactive half-life and bio-logical effect of 32P in the targeting sites were further studied. Statistical analysis was performed with SPSS 12.0, and one-way analysis of variance and t-test were used. Results 32P-CP-PLLA particles were of green cylinder, with regular shape and radionuclide distribution. The RSAC of the particles was of little re-lation with molecular weight of PLLA and proportional to the ratio of PLLA to CP. The extracorporeal release rate increased with the reduction of molecular weight of PLLA and with the increase of the ratio of PLLA to CP. The RRR reached peak when PLLA was 3 times of CP. The 32P-CP, released with the degradation and corrosion of the particle distributed mainly in the surrounding muscles of the particle. And the peak of per-centage activity of injection dose per gram of tissue (% ID/g) in liver, spleen and bone were 1. 7887, 1. 6401 and 1. 9470 respectively, much lower than that in the 32P-CP group (4.7523, 3.9712 and 4.3174 ; all t > 2.7, all P < 0.05). The % ID/g in other organs was much less. The radioactivity effective half-life in the targeting sites increased to about 13 d. There was widespread necrosis around the particles with no ex-istence of normal tissues among them. And no abnormality in spleen and liver was found. Conclusion As a better dosage form of pure β-particle emitter, 32P-CP-PLLA, which can increase the targeting radioactive dosage and effective half-life in the implanting sites, can be served as an potential implanting agent for onco-therapy with a better perspective.     

Mineral and nutritional requirements of preterm infant

Preterm infants are at risk of growth failure and metabolic bone disease due to insufficient nutrient supply in postnatal life. An ample provision of protein, energy, calcium and phosphates through parenteral or/and enteral nutrition is crucial for bone growth and mineralization. Additional vitamin D supplementation improves bone mineralization and enhance intestinal absorption of minerals.     

维持性血液透析患者钙磷代谢紊乱及碳酸钙对血钙磷和iPTH的影响

目的了解维持性血液透析（血透）患者的钙磷代谢情况、全段甲状旁腺激素（iPTH）水平及碳酸钙对血钙磷、iPTH的影响。方法检测42例血透患者血钙磷、iPTH水平,选择血磷〉1．78mmol／L的患者服用碳酸钙12周,观察治疗前后血钙、磷、钙磷乘积及iPTH的变化。结果①在42例患者中,经白蛋白校正过的平均血清总钙水平为（2．30±0．31）mmol／L[（1．50～2．83）mmol／L],其中低钙血症（〈2．10mmol／L）者有8例（19％）,高钙血症（〉2．37mmol／L）12例（29％）;平均血磷水平为（2．20±0．85）mmol／L【（1．21～3．84）mmol／L】,其中高磷患者23例（55％）;平均钙磷乘积（60．00±18．16）mf／dl^2[（31．02～97．56）mg^2／dL^2】,钙磷乘积〈55mg^2／dL^2的患者有15例（36％）;平均iPTH水平为（330．15±262．92）ng,L【（40．8～1322）ng／L],其中〈100ng／L者5例（12％）,（100～300）ng／L者15例（36％）,〉300ng／L者22例（52％）。②服用碳酸钙后,血钙明显升高（P〈0．05）,血磷、钙磷乘积及iPTH均明显下降（P〈0．05）。结论维持性血透患者普遍存在钙磷代谢紊乱及继发性甲状旁腺功能亢进症,碳酸钙对高磷血症及继发性甲状旁腺功能亢进症有治疗作用,但需注意高钙血症的发生。     

急性白血病肝浸润~(31)P磁共振波谱学分析及临床意义

目的:通过对白血病肝脏浸润(LIL)病例与正常对照组的肝脏二维化学位移磁共振31磷波谱成像(2D CSI ~(31)P MRS)对照研究,探讨LIL的肝脏磷化合物代谢特征变化.方法:收集LIL 15例,并与12例正常肝脏作对照,进行2D CSI ~(31)P MRS肝脏扫描,检测各种磷代谢物包括磷酸单酯(PME)、磷酸双酯(PDE)、三磷酸腺苷(ATP)、无机磷(Pi)的相对值,经体模所测校正系数校正后,分析PME、PDE、Pi、ATP的校正相对值(以下简称相对值),及PME/PDE、PME/ATP、PDE/ATP、Pi/ATP、 PME/(PME+PDE)的比值变化.结果:在所测的肝脏磷代谢物相对值中,仅LIL组的PME相对值升高,为1.992±0.876,与对照组(1.167±0.427)相比有显著性差异,P<0.05;其它各磷代谢物相对值均无差异.比较LIL与正常对照组之间磷代谢物比值,发现LIL组中与PME相关的比值包括PME/PDE、PME/ATP和PME/(PME+PDE)比值升高,分别为0.551±0.339、1.402±0.654和0.326±0.13,与对照组(分别为0.254±0.059、0.792±0.232和0.199±0.049)相比有显著性差异,P<0.01;LIL组的其它磷代谢物比值与对照组相比均无显著差异.结论:肝~(31)P MRS检查为LIL提供新的非创伤性检测和评价方法,肝脏PME相对值及其相应比值升高提示白血病患者肝浸润存在的可能.